Previous case reports and non-randomized studies have indicated that inhalation of aerosolized iloprost may offer a new life saving strategy in intractable pulmonary hypertension and ARDS. Further, advantages of inhaled iloprost include the lack of adverse reactions and toxic side effects as well as convenient and more cost-effective administration. Other available therapies like nitric oxide inhalation costs more, around Rs 350/liter and a total of 34-45 liters per patient is required. It is also associated with additional side effects, such as thrombocytopenia. Due to the irreversible nature of ARDS associated with high rate of mortality also affecting resource allocation in critically ill patients, we suggest carrying out this study in our intensive care unit (ICU), where the incidence is > 10% resulting in almost 90% mortality (ICU Quality Indicators Jan-Apr 20048). Iloprost is completely metabolized and excretion of metabolites is primarily via the kidneys; the elimination half-life is 30 minutes. Inhalation therapy reduces systemic absorption and hence elimination half-life.